Wednesday, March 28, 2012

I'm looking at the A123 20AH prismatic LiFePO4 battery as a possible battery for my Tidalforce stable. They have some very good qualities for them.

They are extremely rugged

They are very compact

They have lots of lifecycles (charge/discharge cycles)

They can put out tremendous amounts of power (30C or 600A!)

They are not overly expensive to build a 20AH 36V pack perfect for Tidalforce bike

They are made in the USA!

The first thing you'll notice is that they are in a prismatic package which is very flat and very thin. They are 7.25mm (.3") x 160mm (6.3") x 227mm (8.94") which is roughly (very roughly) a piece of 8.5"x11" paper folded width-wise. The battery is slightly larger then the folded piece of paper.

Even when they are stacked 12 together, they should only be under 4" thick (3.6" with no spacers). Of course, some sort of insulator as a separator would probably be recommended since you don't want the possibility of a short to occur with something that holds this many Amps!

Here is an amazing video test of this pack delivering tons of amperage through a dead short. The battery doesn't miss a beat. The video is very shaky but you'll be amazed as much as I was!

If I do get these cells to make a pack or buy a pre-existing pack, I'll be sure to post it here.

Tuesday, March 20, 2012

There are two major battery manufacturers that Hobbyking.com sells. They are the Turnigy and Zippy brands. I spotted the Zippy 8000mAH pack that would fit inside the front hub shell of the Tidalforce hub battery, but am now having second thoughts since they seem to be overrated in terms of their C rating and they also have higher internal resistance than Turnigy packs. This was discussed in the following Endless-sphere.com thread.

I'll investigate further, but it looks like I'll have to revisit what I can fit inside the front hub! Unfortunately, it looks as if Turnigy doesn't sell a 5S 8000mAH battery. The largest they have in 5S is 5000mAH. Sigh.

Monday, March 19, 2012

I started on the above titled blog post shortly after posting part 1. However, after many words and multiple edits, I didn't think I could do justice to this vast/ever changing topic! I did a quick look to see if there was any site that had comprehensive and well researched information both theoretical and practical real-world knowledge. I came upon my good friend Justin Lemire-Elmore's excellent and highly recommended webiste, ebikes.ca. He has an excellent page on batteries and in particular, batteries for ebikes!

Here, I'll outline the many choices you have available to use a 3rd party battery to replace your worn out or dying Tidalforce front hub battery.

Nickel-Metal Hydride or NiMH

First, the battery type used by Wavecrest Labs, creators of the Tidalforce electric bike is called Nickel-Metal Hydride or NiMH for short. This was a pretty good choice for the Tidalforce bike at the time (early to mid 2000s).

The pros for Nickel-metal hydride are:

They were made from 30 1.2 Volt D sized batteries and good quality NiMH batteries can indeed put out a lot of current when needed.

They didn't need to be babied too much since they didn't have the dreaded "memory effect" of nickel-cadmium or Ni-CAD batteries.

They could be configured in a circular arrangement so that they fit into a hub battery.

They had enough capacity (9AH) to give a medium range ride for the Tidalforce system.

They were lighter than lead acid batteries and didn't have the inherent problems of lead acid batteries (Weight, Peukert effect, limited lifespan, can't be kept left in a discharged state) for electric bikes.

They were readily available, albeit they were relatively expensive at the time (for higher quality cells).

They were a very "safe" chemistry since there were few reports of what seemed like spontaneous combustion issues as we've seen from other battery types.

The cons against nickel-metal hydride are:

They are heavier and bulkier than newer chemistries like lithium-ion (Li-Ion) or lithium polymer (LiPO).

They had a relatively short cycle life (charge/discharge cycles) of about 250-300 cycles.

They had a tendency to self-discharge if left unused.

They had reduced capacity in cold temperatures.

For greatest longevity, they need to be discharged and recharged completely every few months.

If you have parallel packs of NiMH, you need to balance them occasionally.

Lithium Ion or Li-Ion

Lithium ion (Li-Ion) is a newer type of battery and has several advantages over NiMH.

Thursday, March 15, 2012

Well, I took my partially assembled wheel with my precious X motor over to a local electric bike shop last week and they were not able to get it to true. It has been trued left to right, but can't be trued up or down. So it is out of round right now. The tech says that the nipples don't have square shoulders any more and so it's getting difficult to work. I have my doubts. Before I name names and take the motor/wheel back, I'm going to give them one more shot to true it. Let's hope this happens soon. They are now saying they want to replace the nipples with new ones and it may take a while to get them. We shall see.

Monday, March 5, 2012

I've received many requests for help on this topic (How to use an external battery pack with a Tidalforce bike or how to fix my Tidalforce front hub battery), that I thought I would put it into one blog post versus the many that I have on the subject.

First off, you're probably reading this since you have recently come across a used Tidalforce electric bike or currently have a Tidalforce electric bike that has a front hub battery that is either dying or is completely dead! This is pretty common since Tidalforce (also known as Wavecrest Labs) went out of business in 2006 (or thereabouts) and getting replacement batteries is either very expensive or very difficult to do. Many folks give up and just sell their Tidalforce bikes in desperation. They probably loved the bike when it was running and totally enjoyed riding a smooth, quiet, powerful electric vehicle and hate giving up on it, however, there doesn't seem to be much hope for reviving the battery and so they sell their dying bikes for a song.

If you happened across one of these dying Tidalforce bikes, congratulations on your great buy and please read on!

If you've had your Tidalforce for a while and are looking to replace the battery, then please read on.

Let's start with the bad news!

You've probably thought of the possibility of replacing the bad cells inside the front hub and you're wondering if this is possible. The practical answer is no, unless you have lots of electronics experience and some specialized equipment. The special equipment you need is a battery analyzer, a tab welder, and some very high quality NiMH D cells. The battery analyzer is used to test the 30 (or more) NiMH D cells to match them for voltage and capacity. This is critical since any mismatched cells that are either high or low in voltage or capacity will not last long in the pack and any one bad D cell will determine the capacity and longevity of your entire pack. You'll need a tab welder as well to replace the D cells in your front hub. It is not practical to simply replace the defective D cells in your front hub. Any new cells that don't perfectly match your existing cells will guarantee that your rebuilt pack will not last long. The mismatch D cell will either discharge too much current or not enough current and die an early death.

There is also the matter of the technical skill to disassemble a very complex pack and to reassemble it after you've replaced the cells. This is not something that many people can do. Take a look at some of my other posts of my dead packs and you'll see that it is very complex and challenging.

Now, the good news!

All Tidalforce electric bikes, the M-750, M-750X, S-750, S-750X, iO and the iOX, are all capable of using external batteries. You will need a small jumper and some technical skills. Namely, knowledge of batteries and some basic electronics knowledge. Officially, the external battery when sold by Wavecrest Labs/Tidalforce was the "B Battery." The front hub battery was called the "A Battery."

First: WARNING!
You will need to work with some fairly heavy-duty batteries and delicate electronics circuits. Use caution!

Disconnect all connections from this console to any other component on your Tidalforce bike!
There are many connectors leading from this console to the front hub battery, the throttle, and the rear motor. Disconnect them all! That way, you reduce the risk of causing a short or other electrical issue with the system possibly live with electricity!

Let's get started!
After you've disconnected everything, take a look at the console or dashboard. It should look like this:

You will need to dismount this console by loosening or removing the screw holding it to the handlebars and open it up so that you can get access to the circuit inside.

Flip it over to see this:

Carefully look at this arrangement. You'll notice 5 screws, 5 wires and one white plastic insert in an unused wire slot. KEEP TRACK OF THIS PLASTIC INSERT! This insert helps to keep the console water resistant. Without it, water can easily enter and short out your bike! You've been warned!

Now that you have it open, you'll see clusters of wires and flexible cable inside. Ignore all of these. We are looking for one particular set of jumpers inside.

Here's the circuit board without any wiring to show you what jumpers you're looking for. First, look for the block called "Batt2". I have outlined it in red below. After you spot the block, then look for the second set of jumpers close to the "Batt1" connector. I've outlined it with two red lines below.

You will need to jumper those two pins on the circuit board. It's called the "B Battery Jumper."

In order to create this jumper, you can either improvise by looking for a small jumper from your junk PC or hard drive, or create one from the official parts available at places like Mouser.com or Digikey.com.

This is the correct jumper block for the "B Battery" connector on the console.

You will also need some very fine gauge wire in order to jumper across these two pins. 22 or 24 gauge should do the trick. The jumper does not carry any significant current as far as I can tell. It's just a signal wire. It's either present or not.

To show you how small this connector pin is, see the picture here:

That's the pin in the palm of my hand!

To help with crimping this tiny pin, I bought this $9 crimper from my local Radio Shack:

Now, insert this little header block you've just created onto the "Batt1" connector in the console. This is what it should look like.

Make certain that you've got a good connection with the connector and that it's solid in the socket, reassemble the back cover of the console and be sure that no wires are crimped and that the little white plug is in place!

Now that you've enabled the B battery option on the console on your Tidalforce bike, it's time to configure an external battery for your newly em"power"ed Tidalforce! Please check out my next post!

Thursday, March 1, 2012

I just happened upon this Youtube video. It's of the electronics/camera/stereo district near Tokyo called Akihabara. If you don't know Akihabara, you need to add it to your bucket list! It's an electronic do-it-yourselfers complete dream place to be. There are parts of every description: not just one shop, but dozens and dozens of shops for every type of component imaginable. For audiophile stereo buffs, there are department store sized audio stores which cover every imaginable stereo component. I was there in the mid-80s and remember seeing dozens of display cases showing nothing but phonograph needles! Hundreds of them all on display. Ranging from the very inexpensive to the ultra sophisticated, hand-made needles made out of bamboo with custom jewelry-like cases! Now, if you're a photographer, you will lose your mind in Akihabara. There are so many camera shops there where there are row upon row of sales people behind the counter asking you what you'd like to see. They will hand you anything you ask for and you're welcome to touch and play with all the controls. You can then take one with you if you find it suitable. There was literally everything imaginable for you to see. It's mind-boggling.

Anyway, here's a video one person's view of the electronic components stores in the Akihabara district.

Here's a video of the inside of Yodobashi camera in Akihabara. This is of the computer parts and software section. Try to ignore the cheesy music if you can. :)